<!DOCTYPE html>
<html lang="zh-CN">
    <head>
        <meta charset="UTF-8" />
        <title>09_流程控制语句-if-else-案例练习</title>
    </head>
    <body>
        <script>
            var age = prompt('请输入您的年龄');

            if (age >= 18) {
                console.log('来吧');
            } else {
                console.log('走开');
            } 
        </script>
    </body>
</html>